The GCRC represents the only discrete area in San Francisco General Hospital where optimal conditions exist for the conduct of clinical investigation. The facility provides specialized nursing care and a trained staff to assist in the performance of clinical research. The dietary service provides controlled diets of fixed intake for extended periods for metabolic studies. Patient care is at the highest standard to ensure the most conducive environment for the critical observations required. Major study projects are: The role of the mineralocorticoid hormones in acid-base metabolism in normal subjects and patients with chronic renal disease; the mineralocorticoid hormones in hypertension and potassium metabolism; abnormalities of the renin-angiotensin system; prenatal diagnosis of hemoglobinopathies; endocrine events at first pregnancy; pharmacokinetics of digoxin and quinidine; clinical pharmacology of disulfiram and effects on adrenergic function; diazepam kinetics during alcohol withdrawal; sweat ethanol as an index of total alcohol consumption; drug metabolism in renal and hepatic disease; nitrogen balance and effect of keto-analogues of essential amino acids in chronic renal failure: mechanisms of hyponatremia; rhinovirus infections in bronocho spasm.